This invention relates to an apparatus for preparing sets of documents, comprising a folding station, supply means for supplying document sets each consisting of at least one document in spaced succession to the folding station, and control means for controlling the supply means and the folding station.
It is known to use such an apparatus for the purpose of assembling items to be mailed, whereby the documents supplied by the supply means are folded using a folding station and dispensed for further processing. Such an apparatus is known in particular as a configuration possibility of components which are marketed and manufactured by HADEWE B.V. of Drachten, the Netherlands, under the designation "System 7". In the known apparatuses for processing documents the documents are fed to the folding station at a specified fixed interval to prevent the documents from colliding with each other in the folding station or upon leaving the folding station. With a view to operating convenience, in the known apparatus the interval is the same for every processing situation. The fixed interval is therefore generally tailored to the longest document to be processed. This means the interval is tailored to the most unfavorable processing situation, with the result that the apparatus as a whole has a rather low processing speed.
It is one object of the present invention to provide an apparatus without the above-mentioned drawback.
To realize this object, in accordance with the invention, an apparatus of the type described in the preamble is equipped with measuring means for determining a length of a document set or of a space between two successive document sets supplied to the folding station, these measuring means being operatively connected to the control means, the control means being adapted for controlling the supply means such that documents are supplied to the folding station without colliding with preceding documents and with a minimum of interspace.
Such an apparatus, while its operating convenience is maintained, ensures an optimum processing speed of the documents without the documents colliding with each other.
The measuring means can for instance be designed with scanning means comprising a photocell. Such a photocell is a standard commercially available device and is highly reliable in operation.
The known apparatus moreover typically comprises an accumulating position arranged behind the folding station. The accumulating position generally comprises a stop and discharge means. The drawback of the known apparatus with an accumulating position is that the supply means feeding the documents to the folding station and the discharge means of the accumulating position are coupled to each other. In the known apparatus the supply and discharge means are for instance designed as a single endless chain or belt conveyor, so that the supply and discharge of the documents always takes place simultaneously. The folding station is essentially arranged over the conveyor. The associated drawback is that when the conveying means is operated to convey a document, the accumulating position is emptied, one result being that it is impossible to form behind the folding station a stack composed of documents which have been folded in two stages by the folding station. Moreover, coupling the supply means and the discharge means has a retarding effect on the total apparatus. The fact is that when the discharge cannot take place immediately, for instance because apparatus arranged behind the accumulating position is not yet ready for processing documents, the supply is delayed too.
To remove this drawback, in accordance with a further elaboration of the invention an accumulating station is arranged behind the folding station, this accumulating station comprising a stop adapted to be positioned automatically and freely relative to a reference point, and discharge means drivable and controllable independently of the supply means.
Such an "uncoupled" accumulating station has a favorable effect on the processing speed and the processing possibilities of the apparatus. By virtue of the free and automatic positioning of the stop, the accumulating station can process documents of different sizes without requiring manual adjustment activities for this purpose.
For the purpose of supplying documents of mutually highly different lengths, the use of only one supply means may cause unnecessary delay because the processing speed of the entire apparatus is tailored to the longest document to be processed. In order to reduce these unnecessary delays to a minimum, it is particularly advantageous, in accordance with a further elaboration of the invention, if the apparatus comprises a shunting station, the supply means comprising one or more first feeder stations, a conveying means and a second feeder station, the first feeder stations each being designed for feeding documents to the conveying means, the second feeder station being designed for feeding documents directly to the shunting station, the conveying means being designed for feeding documents to the shunting station, the shunting station being designed for feeding documents to both the folding station and the accumulating station.
The term "feeder station" as used herein is understood to mean any station adapted for feeding documents intended for an item to be mailed, for instance a printer, a burster, a feeder station for feeding singulated sheets from a stack or a crossfolding machine for folding a document in longitudinal direction.
The documents fed to the shunting station by the conveying means and the second feeder station can traverse the shunting station along intersecting paths. The timing by which the documents are fed to the shunting station both by the second feeder station and by the conveying means must be such that any documents crossing each other in the shunting station will not collide with each other. Whether the documents collide with each other in the shunting station depends on the length of the documents that are being fed by the second feeder station and the conveying means and on the route which the documents traverse through the shunting station. In some cases it may happen that certain feeder stations do not feed any documents or that, for instance, the documents coming from the second feeder station do not have to be folded. Because of all these possible combinations there are about 300 possible modi in which the apparatus can function. Each mode requires a particular processing speed of the total apparatus.
Precisely in such complex apparatus where at different points collisions between documents can occur, i.e. in the folding station, the shunting station and during the feeding of documents to the conveying means and the shunting station, the advantage achieved through the scanning means and the particular control, i.e., that, while the operating convenience is maintained, the processing speed is adjusted to the instantaneous mode of the apparatus, carries particular great weight, since the processing speed is automatically adjusted to the instantaneous mode of the apparatus without intervention on the part of the operator. Moreover, in the case of such complex apparatus, the separate accumulating station provides the advantage of greater freedom in the choice of the order in which the documents are fed to the shunting station, since now, in contrast with the known apparatus, it is quite well possible that documents located in the second feeder station are the first to be fed to the shunting station.
A constructively and control-technically simple design of such an accumulating station can comprise, in accordance with a further elaboration of the invention, a supporting surface comprising at least one slot extending in the direction of conveyance, at least one endless belt or chain arranged under the supporting surface and extending in the direction of the slot, this belt or chain being drivable in two directions and controllable to be stopped in any position, the belt or chain comprising fingers or similar elements reaching through the slot to above the supporting surface and fulfilling the functions of both stop and discharge means.
Because the fingers function both as stop and as discharge means, the accumulating station need only comprise one driving motor for driving the discharge means and positioning the stop.
According to a further elaboration of the invention, an inserter device may be arranged behind the accumulating station, this inserter device being adapted for inserting a stack supplied by the accumulating station to the inserter device into an envelope, the inserter device and the accumulating station being coupled in such a manner that the stop is positioned relative to the reference of the accumulating station in accordance with the size of the envelope disposed in the inserter device.
Such a design provides a secure positioning of the stop since the documents to be accumulated have a size such that they fit into the envelope.
According to an alternative elaboration of the invention, the control can be designed such that the positioning of the stop is at least dependent on the length of the documents as measured by the scanning means.
The length of the documents as measured by the scanning means could moreover be used for choosing the correct envelope in the inserter device. It holds for this embodiment, too, that the positioning of the stop is securely effected.
The present invention further relates to a method for controlling the apparatus according to the invention.
The known apparatus is so controlled that it functions appropriately for all possible modi. In the known apparatus, the processing speed of the different components, which is the same for all modi, is selected such that for the most unfavorable mode the documents do not collide with each other. In practice, this unfavorable mode rarely occurs. For the other modi the processing speed selected is in essence too low. Accordingly, it holds in practice that the processing speed of the total apparatus is generally lower than would be possible in the mode used.
It is an object of the invention to provide a method without this drawback.
To realize this object, the method is characterized in that the control initially controls at least the supply means at an initial cycle speed, the scanning means measuring the length of document sets or of an interspace between the successive documents, and the control subsequently increases the cycle speed of the apparatus, in such a manner that the interspace between the successive documents is minimized.
Such a method for controlling the apparatus provides an optimum processing speed without detracting from the operating convenience of the apparatus.
To clarify the invention, the method and an exemplary embodiment of the apparatus will now be described with reference to the accompanying drawings.